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Jun 2023
Rifkatu Kambel DogaraCorresponding author
The increasing demand for environmentally-friendly materials has led to a surge in research on the production of biodegradable polymers. In this study, we investigate the synthesis of a biodegradable polymer by graft copolymerization of gum Arabic (GA) and polyethylene glycol (PEG). GA, a natural polysaccharide and PEG, a synthetic water-soluble polymer, were used as the backbone and graft monomer, respectively. The graft copolymerization was carried out using benzoyl peroxide as an initiator and performed under nitrogen atmosphere. The resulting polymer was characterized by Fourier transform infrared (FTIR) spectroscopy, Xray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The FTIR spectra confirmed the formation of the graft copolymer, and TGA analysis showed that the copolymer had higher thermal stability than GA. The DTA thermograms indicated two thermal events. The evaporation of water and organic polyethylene glycol components was measured, and the first mass loss was due to the loss of adsorbed and structural water in the gum Arabic, which occurred between 31.87 and 180°C, while the second, corresponding to the pyrolysis of polyethylene glycol functional groups and polysaccharide decomposition, resulted in a 70% mass loss. SEM morphological analysis of gum Arabic showed aggregates of high irregularity in particle shape. The cracks and holes obtained in the Gum Arabic micrograph disappeared from the new gum Arabic-graft-polyethylene glycol, leaving a smooth surface with scattered particles in the image, which was due to the grafting copolymer. From the XRD patterns, the percentages of the amorphous and crystalline phases were determined. The results show that gum Arabic has a 78% degree of crystallinity, whereas gum Arabic-graft-polyethylene glycol has the lowest value of 51%. Biodegradation activity was observed using the fungus Aspergillus flavus on different days on gum Arabic-g-polyethylene glycol. The results clearly showed inhibition zones with a change in the state of the copolymer from solid to liquid from days 8 to 14. These results indicate that the GA-PEG copolymer has potential as a biodegradable material for use in various applications, such as packaging, agriculture, and medical industries.
Jul 2022 DOI 10.14302/issn.2691-6622.ijar-22-4221
Tadesse TeferaCorresponding author
National Agricultural Biotechnology Research Center, Holotta, Ethiopia
Cyanobacteria are considered as one of the important group of organisms having significant ecological, industrial, and biotechnological importance. Cyanobacteria have gained a lot of atten ion in recent years because of their potential applications in biotechnology. This review presents an overview of uses of cyanobacteria in industry agriculture, environment pharmaceutical and medicinal roles and to provide future prospects of the field of cyanobacteria biotechnology. Nowadays cyanobacteria have gained attention researchers because of their various potential applications such as food and feed pharmaceutical industries in medicine, in bioremediation, soil conditioning, as biopolymers, bio adhesives, bioenergy and biofertilizers. Due to presence of wide spectrum of bioactive compounds cyanobacteria has possesses antiviral, antibacterial, antifungal and anticancer activities. Several strains of cyanobacteria are also rich in food supplements. Further nitrogen fixing and soil conditioning capacity of cyanobacteria attracted researchers. Recent studies have also shown that cyanobacteria have capability to degrade environmental pollutants and are also being used as a promising source of alternative energy. Cyanobacteria has also its limitations through bloom production it influnces on the nutrient availability and usage of phytoplankton plants. This review is an effort to forward the valuable information about the qualities of cyanobacteria and their potential role in solving the agricultural and environmental problems for the future welfare of the planet.Thus more efforts should be made in search of more potential strains of cyanobacteria to ensure maximum production of the desired products.
Feb 2021 DOI 10.14302/issn.2328-0182.japst-21-3700
Y. Alkarib SuadCorresponding author
Department of Pharmaceutics, College of Pharmacy, Karary University, Sudan
Objectives The present study addresses evaluation of acacia-guar gum combination as an enteric former for tablet coating aiming to add knowledge on how develop the ability of enteric forming ability of acacia-guar combination. Methods Five formulations of enteric coating solution incorporating guar gum as delayed release polymers along with film coating material acacia gum followed by CMC and glycerin as plasticizer and coloring agents were prepared to coat placebo tablet cores. Different enteric coating formulations organized in different acacia : guar gum ratios as 1:1, 1:2, 1:3, 1:4 and 1:6 were sprayed on placebo tablets surface resulted different delayed coated tablets (F1,F2,F3,F4 &F5) respectively. General appearance and physical parameters were evaluated of each. Enteric coated tablets that revealed promising properties were subjected to accelerated stability study for 3 months to explore the influences of physical aging on tablet coat properties. Results Physical parameters of enteric coated tablets post coating within the range of pharmacopeia specification. The disintegration test was carried out in pH 1.2 and pH 6.8 at 37ºC. F1, F2 and F3 enteric tablets disintegrated immediately with no acid resistance compared F4 and F5 enteric tablets showed good acid resistance coat with smooth tablet surfaces and no coat defects. F5 formula contain acacia: guar gum as 1:6 ratio showed delayed release for 30min in pH 1.2 and 15min in phosphate buffer. The study statistically analyzed and concluded that, an efficient and stable acacia-guar enteric coat is achievable with no effect on tablets physical parameters. Guar gum at 60% as a delayed tablet coating material capable of protecting the tablets core from being released in acidic media and be release in the alkaline buffer as well as stable coat under accelerated storage for three months.
Apr 2019 DOI 10.14302/issn.2377-2549.jndc-19-2720
El-hoshoudy A.N.Corresponding author
Production department, Egyptian Petroleum Research Institute, Naser City, Cairo, Egypt.
Currently, enhanced oil recovery (EOR) acquire increased attention to recover more residual oil trapped after the primary and secondary process in petroleum reservoirs. EOR comprise different technologies involving chemical, thermal, miscible flooding techniques. Chemical flooding by the polymer is a widely implemented method on the academic and industrial scale. In this chapter, the authors discuss polymer flooding using polyacrylates that involve hydrolyzed polyacrylamide (HPAM), hydrophobically associated polyacrylamides (HAPAM), which grafted with different vinyl monomers such as acrylic acid, methyl methacrylates, and 2-acrylamido-2-methylpropane sulfonic acid (AMPS). These polymers increase the viscosity of injected brine solutions, as a result, decrease mobility ratio and enhance sweeping efficiency, so the water act as a piston, which pushes oil in front of it, and consequently increase the recovery factor. The advantages and disadvantages of these polymers as well as comparing different flooding scenarios are reported.
Aug 2018 DOI 10.14302/issn.2377-2549.jndc-18-2187
Randjbaran EliasCorresponding author
Aerospace Manufacturing Research Centre (AMRC) Level 7, Tower Block, Faculty of Engineering 43400 UPM, Serdang, Selangor, Malaysia
Among the numerous potential uses of carbon nanotubes (CNT), its utilization to fortify polymers was given careful consideration. This reason can be because of the remarkable firmness, magnificent quality, and the low thickness of CNT. This has given various chances to the innovation of new material frameworks for applications requiring high quality and high modulus. Exact control over preparing factors, including safeguarding flawless CNT structure, uniform scattering of CNT inside the polymer grid, compelling filler– lattice interfacial communications, and arrangement/introduction of polymer chains/CNT, add to the composite strands' unrivalled properties. Consequently, manufacture techniques assume an imperative part in deciding the composite filaments' microstructure and extreme mechanical conduct. The present best in the class of polymer/CNT elite composite filaments, particularly concerning processing– structure– execution, were looked into in this commitment. Future requirements for material by configuration approaches for handling these nano-composite frameworks were likewise examined.
Jul 2018 DOI 10.14302/issn.2831-8846.j3dpa-18-2207
Dehghanghadikolaei AmirCorresponding author
Oregon State University, USA
Additive manufacturing (AM) is reshaping fabrication in engineering and clinical settings. This editorial highlights metal AM routes—SLS, SLM, DMLS, and EBM—and their application to patient-specific NiTi implants, where biocompatibility and shape-memory behavior are compelling. We note the current gaps that matter in practice: process parameter tuning, post-processing (heat treatment, coating, machining/finishing), and their effects on mechanical performance and corrosion. We invite contributions that quantify these trade-offs and expand AM beyond metals into polymers and ceramics, with clear comparisons across processes and materials. Our goal is to surface actionable findings that improve part quality, reliability, and clinical/industrial readiness.
Nov 2013 DOI 10.14302/issn.2328-0182.japst-12-119
Nath BipulCorresponding author
Department of Pharmaceutical Sciences, Dibrugarh University, 786004, Assam, India
The purpose of the research is to evaluate Sterculiaurens gum as a carrier for oral colon targeted drug delivery system. Sterculia gum has been reported to have wide pharmaceutical applications such as tablet binder, disintegrant, gelling agent and as a controlled release polymer, but it has not been exploited as colon targeting carrier. For evaluation as a carrier for colonic delivery of drugs characterization of gum was done. Microflora degradation studies of gum were conducted in phosphate buffer solution (PBS) pH 7.4 containing rat caecal content under anaerobic environment. Solubility, swelling index, viscosity and pH of the polymer solution were determined. Different formulation aspects considered were: gum concentration (10–40%), concentration of citric acid (10–30 %) on swelling index and in-vitro drug release. The results of the isothermal stress testing (IST) shows no degradation of samples of model drug, azathioprine, in the drug polymer mixture and the core tablet excipients. DSC and FT-IR study has proved the compatibility of the drug with Sterculia gum and other tablet excipients. Microflora degradation study revealed that Sterculia gum can be used as tablet excipient for drug release in the colonic region by utilizing the action of enterobacteria. Sterculia gum exhibits premature drug release in the upper GIT without enteric coating and may not reach to the colonic region. From the study, Sterculia gum as colon targeting carrier is possible via coating with chitosan/Eudragit mixed blend polymers which would provide acid as well as intestinal resistance; but undergo enzymatic degradation once it reaches the colon.